Rotary press

ABSTRACT

A rotary press for smoothing or embossing leather and like flat objects has a rotating pressure cylinder which cooperates with a concavely cylindrical trough on a stationary anvil. The object to be pressed passes through the trough between the cylinder and a laminar belt arrangement moving at the circumferential speed of the roller. The belt arrangement includes an abrasion resisting metal drive belt slidingly engaging the anvil, and a supporting belt of resilient material interposed between the drive belt and the pressed object.

United States Patent lnventors Appl. No. 747,162 Filed July 24, 1968Patented Feb. 16, 1971 Assignee Strojosvit narodni podnik Krnov,Czechoslovakia Priority Aug. 7, 1967 Czechoslovakia 5,679/67 ROTARYPRESS 4 Claims, 2 Drawing Figs.

U.S. Cl. 100/ 153, 100/156 Int. Cl. 83% 3/00, B30b 5/04 Field ofSeareh100/151. 152, 154, 168, 172, 176,210; 69/48; 101/3; 18/10; 100/153, 156

Karel Bajak; I Vaclav Oplustil, Krnov, Cuchoslovakia [56] ReferencesCited UNITED STATES PATENTS 838,615 '12/1906 Goldman l. 100/153X1.176.609 3/1916 Scott 100/156 Primary E.raminer Edward L. RobertsAttorney-Richard Low ABSTRACT: A rotary press for smoothing or embossingleather and like flat objects has a rotating pressure cylinder whichcooperates with a concavely cylindrical trough on a stationary anvil.The object to be pressed passes through the trough between the cylinderand a laminar belt arrangement moving at the circumferential speed ofthe roller. The belt arrangement includes an abrasion resisting metaldrive belt slidingly engaging the anvil. and a supporting belt ofresilient material interposed between the drive: belt and the pressedobject.

ROTARY PRESS BACKGROUND OF THE INVENTION This invention relates to thefinishing of leather and particularly to a rotary press for unfinishedleather and'like flat objects.

In the finishing of leather,.the' unfinished material is compressed toimprove its mechanical properties, to change its dimensions, and to giveit a desired surface finish. Both smooth and textured surfaceconfigurations are produced by high pressure with or withoutsimultaneous heating.

The machinery available heretofore is of two general types. In one type,leather is pressed between two hydraulically operated platens. Thisarrangement permits any desired dwell time in the pressure zone to bechosen. However, it can be used only in a batch operation and has allthe known economical disadvantages of such operation. It is not possibleto treat large pieces of unfinished leather in a single pressing stepbecause of practical limitations of the available hydraulic equipmentand the corresponding limitations on platen size. When complex patternsare to be embossed on the leather, it is almost impossible to obtainproper registration between the several separately embossed portions ofthe pattern;

The second type of known machinery is equipped with pairs of pressurecylinders forming a nip for continuous passage of the flat object to bepressed. The operation is continuous, but

the dwell time of the object in the nip is so short if a reasonableproduction rate is to be achieved that the patterning possi- T bilitiesof the device are extremely limited.

The object of the invention is the provision of equipment for pressingleather and similar flat objects which combines the. aforedescribedadvantages of the two types of known presses,

yet is free of their shortcomings.

SUMMARY OF THE INVENTION The invention provides a single pressurecylinder mounted on a support for rotation about its axis. The cylindercooperates with an anvil fixedly mounted on the support and defining atrough of arcuate cross section transversely of the cylinder axis. Abelt arrangement is mounted on the same support for translatory movementover the anvil in sliding engagement with the trough. The machine driverotates the cylinder about its axis and simultaneously moves the beltarrangement over the anvil at a speed substantially equal to thecircumferential speed of the cylinder while the cylinder is being urgedunder pressure toward the belt arrangement and the trough.

The belt arrangement may include a driving belt and a superimposedsupporting belt, the former engaging the trough during belt movement andthe latter facing the cylinder and defining with the same a gap ofsubstantially uniform thickness in a radial direction relative to thecylinder axis when the cylinder is in its operative position in whichits axis coincides with the axis of curvature of the trough.

The belts are preferably continuous and extend in loops.

Other features, additional objects, and many of the attendant advantagesof this invention will readily be appreciated as the same becomes betterunderstood by reference to the following detailed description of apreferred embodiment when considered in connection with the appendeddrawing.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1. shows a leather finishing press of the invention in sideelevation; and

FIG. 2 shows working elements of the press of FIG. 1 on a larger scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing indetail, and initially to FIG. I, there is seen a rotary press of theinvention which has certain features in common with a rolling mill ofthe type used in steel mills.

The press shown has a heavy frame 1 whose upright sidewalls 2 areapertured. The two sidewalls 2 are connected by a heavy cross member oranvil 3 shaped to resist bending under vertically applied stresses. Thetop of the anvil 3 forms an upwardly open trough which is cylindricallycurved in part. Two cylindrical rolls 4, 4 are mounted on the front andrear of the frame 1 between the side walls 2.

A flexible endless steel drive belt 5 is trained in a closed loop overthe rolls, 4,4 and the trough of the anvil 3, and is kept undersufficient tension for driving engagement with the roll 4, the roll 4'being an idler and mounted in bearings which may be adjusted toward andaway from the roll 4 in a forward and backward direction in a manner notshown in the drawings. Guide rollers 6,6 are rotatably attached to theframe 1 in a nonillustrated manner in front of the roll 4 and behind theroll {to guide a supporting rubber belt 7 in a loop over the rolls 4,4and through the trough of the anvil 3 on top of the steel belt 5.

A bearing block 8 is vertically guided in the aperture of each sidewall2 to support a pressure cylinder 9 above the trough in the anvil 3. Eachbearing block 8 is secured to the transverse top member 12 of the frame1 by a hydraulic cylinder 10 which encloses a piston, not itself visiblein the drawings. A piston rod 10 projects axially from both ends of thecylinder 10. The downward stroke of the piston rod 10 on which the block8 is fastened is limited by adjustable nuts 11 on the threaded endportion of the rod which projects upward from the transverse framemember 12.

A variable speed motor 13 drives the roll 4 by means of a chain 14, anddrives the cylinder 9 by means of a sprocket 17 on a countershaft andconnecting chains 15, 16. The transmission ratio of the several chaindrives is chosen in such a manner that the circumferential speed of thecylinder 9 is equal to the translatory speed of the drive belt 5.

As is better seen in FIG. 2, the cylindrically curved portion 19 of thetrough in the anvil 3 is centered approximately in the axis of rotationof the cylinder 9 when a piece 18 of unfinished leather passes the gapbetween the supporting belt 7 and the cylinder 9 above the troughportion 19 of the anvil 3. The leather, while traveling through thepressure zone is reduced in thickness.

The press may be operated by the motor 13 at a belt speed of one tothirty meters per minute,"and the dimensions of the press are such thatthe resulting dwell time of thetreated piece 18 in the high-pressurezone at 19 is 15 to 0.5 seconds. In an actual embodiment of the press,the hydraulic cylinders 10 produce in the zone a pressure which may beadjusted between 20 and kg per square centimeter (about 300 to 2,200lbs./sq.in.). Moreover, the press is equipped with interchangeablecylinders 9 some of which have smooth surfaces whereas the working facesof others, not shown, are engraved to produce a desired grain pattern inthe leather piece 18, and equipped with hollow trunnions for connectionto a steam line in a manner well known in itself.

There is no relative movement between the surface of the cylinder 9,-theleather piece 18, and the belts 5,7 while the leather passes thepressure zone at 19. The resilient rubber belt 7 yields sufficiently tocompensate for any variation in the thickness of the leather piece 18and is protected against abrasion by frictional contact with the anvil 3by the steel belt 5. The contact area of the latter with the anvil ismuch smaller than the contact area with the drive roll 4. It istherefore possible to provide a lubricant film at the interface of theanvil and of the belt 5 without significant loss of traction at thedrive roll 4.

The illustrated press provides the dwell time in the highpressure zonewhich is necessary for producing'many grain patterns on leather. ltavoids relative movement of the leather and of the pattern forming dieor cylinder 9 in the high-pressure zone, and therefore permits finedetail in the pattern to be faithfully reproduced. The leather isuniformly treated, and the pattern extends continuously over the entireleather surface.

This is achieved in continuous operation with a minimum of manual labor.The leather pieces are merely placed by an operator or by an automaticfeeding conveyor, not shown, on the portion of the belt 7 at the rearend of the machine between the idler roll 4 and the associated guideroller 6, and the pressed or embossed leather piece is discharged overthe front roller 6.

Similar advantages are achieved with the use of smooth-surfacedcylinders 9 which produce a corresponding uniform finish on pressedleather pieces. The fact that the leather is stressed exclusively atright angles to its surface while passing through the press illustratedis believed to account for the superior appearance and mechanicalproperties of the processed leather.

We claim:

1. A press for leather and like flat objects comprising, in combination:

a. a support;

b. a pressure cylinder having an axis and mounted on said support forrotation about said axis; c. anvil means fixedly mounted on said supportand defining a trough of arcuate cross section transversely of saidaxis;

d. belt means mounted on said support for translatory movement over saidanvil in sliding engagement with said trough;

e. pressure means for urging said cylinder under pressure toward saidbelt means and said trough; and

f. drive means for rotating said cylinder about said axis and forsimultaneously moving said belt means over said anvil at a speedsubstantially equal to the circumferential speed of said cylinder.

2. A press for unfinished leather and like flat objects comprising, incombination:

a. a support;

b. a pressure cylinder having an axis and mounted on said support forrotation about said axis; c. anvil means fixedly mounted on said supportand defining a trough of arcuate cross section transversely of saidaxis;-

d. belt means mounted on said support for translatory movement over saidanvil in sliding engagement with said trough; said belt means includinga belt member and a supporting belt member superimposed on said drivingbelt member, said driving member engaging said trough during themovement of said belt means, and said supporting belt member facing saidcylinder;

e. pressure means for urging said cylinder under pressure toward saidbelt means and said trough; and

1. drive means for rotating said cylinder about said axis and forsimultaneously moving said belt means over said anvil at a speedsubstantially equal to the circumferential speed of said cylinder.

3. A press as set forth in claim 2, said trough being of substantiallycylindrically arcuate shape, said pressure means including means formoving said cylinder into a position in which the axis thereofsubstantially coincides with the axis of curvature of said trough, andsaid supporting belt member and said cylinder define therebetween a gapof substantially uniform thickness in a radial direction relative tosaid axis.

4. A press as set forth in claim 3, said belt members each extending ina continuous loop.

1. A press for leather and like flat objects comprising, in combination:a. a support; b. a pressure cylinder having an axis and mounted on saidsupport for rotation about said axis; c. anvil means fixedly mounted onsaid support and defining a trough of arcuate cross section transverselyof said axis; d. belt means mounted on said support for translatorymovement over said anvil in sliding engagement with said trough; e.pressure means for urging said cylinder under pressure toward said beltmeans and said trough; and f. drive means for rotating said cylinderabout said axis and for simultaneously moving said belt means over saidanvil at a speed substantially equal to the circumferential speed ofsaid cylinder.
 2. A press for unfinished leather and like flat objectscomprising, in combination: a. a support; b. a pressure cylinder havingan axis and mounted on said support for rotation about said axis; c.anvil means fixedly mounted on said support and defining a trough ofarcuate cross section transversely of said axis; d. belt means mountedon said support for translatory movement over said anvil in slidingengagement with said trough; said belt means including a belt member anda supporting belt member superimposed on said driving belt member, saiddriving member engaging said trough during the movement of said beltmeans, and said supporting belt member facing said cylinder; e. pressuremeans for urging said cylinder under pressure toward said belt means andsaid trough; and f. drive means for rotating said cylinder about saidaxis and for simultaneously moving said belt means over said anvil at aspeed substantially equal to the circumferential speed of said cylinder.3. A press as set forth in claim 2, said trough being of substantiallycylindrically arcuate shape, said pressure means including means formoving said cylinder into a position in which the axis thereofsubstantially coincides with the axis of curvature of said trough, andsaid supporting belt member and said cylinder define therebetween a gapof substantially uniform thickness in a radial direction relative Tosaid axis.
 4. A press as set forth in claim 3, said belt members eachextending in a continuous loop.